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No. 105: Environmental monitoring in 2013 at the cryolite mine in Ivittuut, South Greenland

Bach, L., Asmund, G. & Riget, F. 2014. Environmental monitoring in 2013 at the cryolite mine in Ivittuut, South Greenland. Aarhus University, DCE – Danish Centre for Environment and Energy, 32 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 105. http://dce2.au.dk/pub/SR105.pdf

Summary

In Ivittuut at Arsuk Fjord in South Greenland the mineral cryolite was mined, sorted and shipped out from 1854 to 1987. The mining operations have caused pollution with lead and zinc in the fjord. The main source is related to waste rock, which was left at the coastline and is still continuously releasing lead and zinc to the fjord from tidal water action.

The pollution of the fjord has been monitored since 1982. Since 1985 the monitoring has only included brown seaweed and blue mussels, since earlier studies revealed no elevated levels of lead and zinc in fish and prawns from the fjord.

This report presents the results of the latest environmental study, which was carried out in July 2013. The geographical pattern of lead and zinc levels found in brown seaweed and blue mussels in 2013 showed that waste rock deposited at the coastline in Ivittuut is still the main source of the pollution from the old mine. In brown seaweed elevated lead levels were found on a ca. 4 km stretch of coastline in eastern Arsuk Fjord around Ivittuut, whereas zinc levels were elevated on most of the coastline studied in Arsuk Fjord. In blue mussels elevated lead levels were found in all of the studied parts of Arsuk Fjord, and also on coasts 3-4 km outside Arsuk Fjord. Zinc levels in blue mussels were elevated only at Ivittuut.

Along a stretch of coastline of ca. 5 km around Ivittuut the lead concentrations in blue mussels were found at levels so high that it is recommended not to collect blue mussels for human consumption. The size of this area is similar to what was found in 2007 and 2010, but smaller than in 2004 and much smaller than what was found in the period 1982-1992. During the period of 1982-1992 the recommendation not to collect mussels also included part of the western coastline of Arsuk Fjord.

Over the entire monitoring period from 1982 to 2013 a decline in pollution has been observed for lead levels in both brown seaweed and blue mussels in Arsuk Fjord. Whereas lead concentrations have decreased ca. 3 times since 1982, the concentrations of zinc have also generally decreased, but at a slower rate.